First time flying a rc plane(but i do fly helicopters)and i started with a pop wing. First time building one first time flying one. My maiden flight went well except for the fact that my wing wanted and did fly upside down. I think put it together just like the manual said. So what have i done wrong?

Did it roll upside down sideways or loop front to back. One thing is looks like your control horns are too far back. That reduces the control throw.

The trick with the Popwing is getting the CG right relative to the elevon position. What battery are you using and did you add any extra nose weight? The design tends to be tail heavy with any battery that fits in the pocket. Tail heavy plus some up elevon will leans to a rapid loop over. If you really balance where they say, yoo need a lot of up trim to get level flight otherwise it nose dives when you launch it. I found its better to start with it tail heavy, get it flying and then gradually add nose weight until it trims with some up reflex.

if it rolled sideways then your elevons were uneven. You can site sideways across the wing and use trim to get them level with each other. This does not help with where they need to be up/down but it should stop or slow the roll. The only other possibility is some how way off balance from the center line. Hard to see how that could be so its probably your elevons being uneven. Once you can get it airborn, you have to usually act fast to get it fully trimmed. If you can't trim it fast enough while flying, bring it down remembering which way it need to be trimmed, add some trim and repeat.

Note, I have the control arm holes lined up with the hinge line and even that does not give as much elevon travel as the manual suggest.

Okay, I get it now... Sounds like your servos are too weak for the speed. Usually metal gear 9 grams do the trick, not sure if you are using them or not. High speed loads the elevons pretty good and a weak servo will stall under the load and not move until you slow down.

The 420 was a joke. I'm making an assumption it has another meaning. Maybe I was wrong

my servos are 11g mg servos, and i believe them to be plenty strong...i have found the weak spot, in the control rod. under load i tested it with my hands, it bends...so LHS and gonna pick up some thick gauge wire.

my servos are 11g mg servos, and i believe them to be plenty strong...i have found the weak spot, in the control rod. under load i tested it with my hands, it bends...so LHS and gonna pick up some thick gauge wire.